A GEOSPATIAL INVESTIGATION OF BREAST CANCER TREATMENT Abstract Clear racial disparities in breast cancer exist with African American (AA) women living in the US being less likely to be diagnosed with breast cancer (BrCA) in comparison to European American (EA) women, yet more likely to die from BrCA. Previous work by this team has demonstrated that South Carolina, in particular, is a region of extreme disparities, especially breast cancer mortality disparities. Access to appropriate treatment once breast cancer is diagnosed, a key factor linked with increased survival, may help to explain these disparities. We propose to apply geospatial methodologies in innovative ways to the problem of breast cancer disparities among African American women. This represents an area that has never to our knowledge been explored and has the potential to introduce a new paradigm in the conceptualization of minority cancer disparities. Considering this, we plan to examine breast cancer treatment and mortality patterns among a racially and geographically (urban vs. rural) cohort of women residing in South Carolina. To begin this work, we will create a cohort of women unlike any other cohort that has been previously available or researched. We propose to link data sources to include the South Carolina State Employee Health Plan, South Carolina Medicaid, South Carolina's Breast and Cervical Cancer Early Detection Program, and the South Carolina Central Cancer Registry. These high-quality data sources have never been linked in this manner to explore breast cancer care in rural and minority women. Additionally, we will explore the impact of various geospatial measures such as distance to the treatment facilities, economic stress, and segregation on upon receipt of breast cancer care and mortality. Unlike previous research in this area, this cohort will consist of a large number of rural, AA women. We anticipate that more than 15,000 breast cancer cases will be available for analysis after linkage, providing us with the necessary numbers to insure that we have sufficient power to detect significant differences in our cohort of women. Additionally, this rich data source will allw us to calculate the distance women traveled from their home residences to the specific treatment facility they attended, overcoming a limitation of previous studies where the exact facility attended was not known. In conclusion, the proposed research will build on a limited body of research pointing to the importance of geography and neighborhoods on treatment services in explaining breast cancer disparities observed in AA women and may offer an important avenue through which this disparity gap can be narrowed.